Click on either icon  to return to BIRDNET  home page

Issue Brief from the Ornithological Council

Volume 1
Number 6:

THE SALTON SEA: A BIRD'S EYE VIEW

THE ISSUE

 In the rush to "save" the Salton Sea, several points must be kept in mind:

1. The Salton Sea ecosystem is not a homogenous mass of water, but a complex mosaic of fresh, brackish and salt water habitats. Despite the "crisis" of the die-offs and increasing salinity, the Salton Sea and its associated wetlands continue to provide essential wetland habitat for significant numbers and a great diversity of migratory and breeding waterbirds. This habitat is de facto mitigation for the 92-99% of wetlands that have been destroyed in the region.

 
2. The Salton Sea represents a region wide, international conservation challenge.

 
3. The major biodiversity needs of the Salton Sea and the entire Rio Colorado Delta Region are to stabilize the situation (reversing trends of decreased water quality) and then to provide more water and space for fish/wildlife management and habitat restoration.

 
4. Engineering and rehabilitation solutions for the Salton Sea will have unknown, but likely, significant impacts on the continued existence of the highly diverse, abundant and dynamic bird populations that are dependent on the Sea and associated habitats. There is a risk that "restoration" may have unintended consequences that will reduce the value of the Salton Sea as habitat for birds and other wildlife.

 
5. The Salton Sea's complex ecological issues require thoughtful and careful study over a period of years. The scientific basis of the current Salton Sea "crisis" needs careful examination to determine its severity, causes, and time frame.

 
6. Successful rehabilitation plans require a solid scientific foundation based on rigorous ecological and hydrological study, and will result from the combined efforts of local and federal agencies, lawmakers, academics, NGOs, and other private concerns from the United States and Mexico.

 
7. The process to be initiated now to stabilize the situation and reverse negative trends must be undertaken with flexibility to adjust management as new information is gained from long-term research and monitoring.

LEGISLATION

This action is the latest in a series of studies and task forces that began in the mid-1960s. In 1993, a Salton Sea Authority was formed of local counties and water districts as the lead local agency to develop programs to continue beneficial use of the Sea. These uses include agricultural and wastewater repository, protection of migratory birds, fisheries, and endangered species, and recreation. In December 1997, Interior Secretary Babbitt formed a joint governmental coordinating mechanism (Research Management Committee) and began an open environmental review under the National Environmental Policy Act to identify to identify and evaluate options for addressing the issues of the Sea. At this time, a Salton Sea Science Subcommittee was formed to provide the synthesized science to support the environmental review.

SCIENTIFIC ISSUES

1. The Salton Sea represents a region wide conservation challenge that is entirely of an international nature. What happens at the Salton Sea and in the rest of the Colorado River delta region affects habitats in Mexico, and vice versa.

 
2. A major issue through the history of the Salton Sea involves the significant loss of wildlife habitat in the region overall, including the loss of 92-99% of original wetland habitats. Any restoration plan must consider the sensitivity of nesting species (mitigation for loss of nesting islands will likely be necessary) as well as those of wintering and migrating birds, and provide safeguards that minimize the impacts posed by construction, recreation and shoreline development.

 
3. Land acquisition is a key element in the conservation of biodiversity in the entire region, not just the Salton Sea. Some important habitat "islands" (real islands and patches of habitat) are presently unprotected. A key issue will be the need to ensure wetland acquisition and maintenance.

 
4. Perhaps the biggest of all issues is the future of water availability. Many forces are causing the ever-increasing demands for fresh water. Natural resource conservation interests, such as wildlife management agencies are almost never given any kind of priority. Management plans need to take account of the likely reduced water supply in the future.

 
5. Human population growth (both U.S. and Mexico) is a continuing significant force restricting water availability. 20 year projections are for a doubling of population in the Salton Sea watershed and a 50 percent increase in southern California.

 
6. At the Salton Sea, and to lesser degrees in all other parts of the Rio Colorado Delta Region, increasing salinity is a CERTAINTY. Evaporation and constant reuse of water are causing the increases in salinity and chemical content. Changes in salinity have allowed the Salton Sea in its brief history to remain an ever-important system, but a dynamic and ever-changing system for bird, fish, and other types of biodiversity.

 
7. Many exotic species have entered the system. Some, such as the fish Tilapia, may be important in supporting the spectacular populations of fish-eating birds. Tilapia is in the entire system nearly all the way down to the head of the Gulf of California. Cold weather is likely responsible for many of the kills of Tilapia, most of which were also infected with bacteria.

 
8. Environmental changes due to reduction of water flow upriver, such as the now widespread exotic salt cedar (largely at the expense of native cottonwoods and willows) will also affect terrestrial bird habitats.

 
9. Disease problems are among the major issues, especially at the Salton Sea. Disease is an OUTCOME, not a cause, resulting from an ecosystem under stress. Although the die-offs of birds has led to the present attention for the Salton Sea and to current proposals for reduction of salinity, reduction of salinity alone is unlikely to stop the disease problem. More information is needed to better understand the dynamics.

 
10. The issues of limited water and habitat availability are similar through the entire Colorado River Delta region. A major regional effort is needed. It is unlikely that any activities that do not involve the Mexicans as key players will effectively achieve their goals.

BACKGROUND

The Salton Sea basin is the main U.S. watershed of the international Colorado River delta, whose 8600 sq. km. include the Coachella, Imperial and Mexicali valleys, and the lower Colorado delta terminating at the Sea of Cortez.

The Salton Sea ecosystem has long been recognized as providing significant wetland habitat for immense numbers of migrant, wintering, and breeding waterbird birds. Despite recent die offs, the ecosystem continues to provide essential habitat for the survival of millions of birds. More than 350 species of birds have been seen at the Salton Sea and its surrounding lands. Birdwatchers and others visiting the Salton Sea National Wildlife Refuge alone brings in $3.1 million to the local economy annually.

Recent surveys have revealed populations of up to 1.5 million Eared Grebes in midwinter, up to half of California's wintering White-faced Ibis, tens of thousands of migratory shorebirds, waterfowl, and American White Pelicans, as well as significant breeding colonies of Double-crested Cormorants and Caspian Terns, nearly 40% of nesting Black Skimmers in California, and the largest of only two breeding populations of Gull-billed Terns in the western United States. Significant colonies of herons and egrets, as well as the recently established Brown Pelican, have thrived during the 1990s.

The State of California and surrounding regions lost millions of acres of wetlands to agriculture, including coastal wetlands, interior wetlands (most notably the Colorado River delta and Tulare Lake basin), and interior saline lakes such as Owens Lake, so that only 1-8% of the original remains. The Salton Sea, despite its artificial genesis, serves as de facto mitigation on a regional if not continental scale.

The Salton Sea is a dynamic, highly complex, and poorly understood ecosystem. Attention to date has focused largely on outbreaks of mortality due to a variety of diseases. Since 1994, a total of quarter of a million birds may have been killed, including an estimated 150,000 Eared Grebes in 1992 (from an unknown cause, most likely algal toxins) and more than 10% of the western population of American White Pelicans and more than 1,000 endangered Brown Pelicans in 1996 (from an unusual form of avian botulism). The environmental and biological factors that have led to the outbreaks are poorly understood, but clearly indicate a stressed ecosystem. There are now large algal blooms in this warm, shallow, alkaline basin due to inputs of sewage. However, the relationships between water quality, the potential role of biotoxins, and fish and bird mortality remain virtually unknown. Few published accounts of the species of the Salton Sea exist. Studies of fish and invertebrate faunas of the 1950s and 1960s are now likely outdated.

The Salton Sea is a human-modified ecosystem, being maintained by human actions for a variety of purposes, none of which existed for this area during the 19^th century. The stated objective of the Salton Sea project are:

1. Maintain the Sea as a repository for agricultural drainage.
2. Provide a safe, productive environment for resident and migratory birds and endangered species.
3. Restore recreational uses of the Sea.
4. Maintain a viable sport fishery.
5. Provide opportunities for economic development along the shoreline.

For further information:

The Center for Inland Waters at San Diego State University maintains a website at http:/www.sci.sdsu.edu/salton/SaltonBasinHomePage.html (Note that the address of this most comprehensive and authoritative source of information is case sensitive. Capitalize exactly as shown.)

Audubon magazine, May 1998. pp 82-89. Frank Graham. Midnight at the Oasis.

Washington Post. Aug 1, 1997. page A1. William Booth. Proposed cure for California environment blunder mired in controversy.

References
Collins, C. T., and Garrett, K. L. 1996. The Black Skimmer in California: an overview. W. Birds 27: 127-135.

Glenn, E. P., C. Lee, R. Felger, and S. Zengel. 1996. Effects of water management on the wetlands of the Colorado River Delta, Mexico. Conservation Biology       10(4):1175-1186.

Grinnell, J. 1908. Birds of a voyage on Salton Sea. Condor 10: 185-191.

Jehl, J., Jr. 1988. Biology of the Eared Grebe and Wilson's Phalarope in the nonbreeding season: a study of adaptations to saline lakes. Studies in Avian Biol. 12.

_____. 1994. Changes in saline and alkaline lake avifaunas in western North America in the past 150 years. Studies in Avian Biol. 15: 258-272.

Johnson, N., and Jehl, J. Jr. 1994. A century of avifaunal change in western North America: overview. Studies in Avian Biol. 15: 1-3.

Molina, K. C. 1996. Population status and breeding biology of Black Skimmers at the Salton Sea, California. W. Birds 27: 143-158.

Page, G. W., Shuford, W. D., Kjelmyr, J. E., and Stenzel, L. E. 1992. Shorebird numbers in wetlands of the Pacific Flyway: a summary of counts from April 1988 to January 1992. Point Reyes Bird Observatory, 4990 Shoreline Hwy, Stinson Beach, CA 94970.

Shuford, W. D., Hickey, C. M., Safran, R. J., and Page, G. W. 1996. A review of the status of the White-faced Ibis in winter. W. Birds 27:169-196.

Sykes, G. 1937. The Colorado Delta. Carnegie Inst. Washington. Pub. No.460. 193 pp.

This publication was reviewed by professional ornithologists and other scientific experts under the auspices of the Ornithological Council. You may contact the Council for further information.

Citation: Ornithological Council (1998). The Salton Sea: A Bird's Eye View. Bird Issue Brief Vol. 1, No. 6, 3rd Edition.